EGR help... Options

[brandon702bmx]

Hi. I own a 1994 Celica GT and there's something that's been plaguing my car of recent. I have this problem that is EGR related and I can't figure it out. I get a check engine light that comes on and goes off at random points of time. Really strange. I jumped the terminals (I'm pre-OBD2) and I get 7 flashes with a pause with 1 more flash. Code 71. I did a bit of research on the code and it leads directly to the EGR. I reconnected lines that were disconnected. One thing I particularly noticed was that whenever I hook the vacuum hose from the EGR regulator to the EGR valve, after a while it gets blown off. It's really odd. I've reconnected it about 3 times, so apparently somethings wrong there. I'd also like to list the symptoms of the car to maybe help narrow it down to someone that actually may know what's wrong. When the car gets started after sitting overnight, it runs great. After I drive it a bit pressing the accelerator seems to give it the feeling that it's starving for fuel

Symptoms:
Poor fuel efficiency (100 miles/half tank)
CEL comes and goes at random
Car runs great at first start, after awhile... runs VERY bad kind of like a starve for fuel.

So the one thing I did narrow it down to is a bad/clogged catalytic converter. I've also thought about a bad o2 sensor... but I don't think it would cause the check engine to come on and off and make the car run terribly after a while. Do these symptoms sound about right? I don't want to just replace things for the sake of replacing them. Especially the cat because it's rather pricey.

This post has been edited by brandon702bmx: Apr 18, 2017 - 11:10 PM

[Bitter]

If you take out the pre-cat O2 sensor and drive a short distance does it behave better? That would create an exhaust leak to relieve excess pressure, or you could loosen the bolts and flange at the cat, but the O2 is probably easier. It can also be an issue with the big disc that operates the EGR valve, those modulators frequently go bad.

[HardHead93]

When I had an EGR code on my 5sfe it was the diaphragm inside the EGR valve was torn and not opening and closing properly. I was also having the same problem with vacuum hoses coming off. I have an extra EGR valve that is fairly new. If it points to that issue PM me and we can work something out. I know this EGR valves can be expensive.

[brandon702bmx]

Okay so that might be a possibility. I did remove the throttle body from the intake manifold to clean it. I reachd my finger in there where the EGR meets the manifold itself and it was completely plugged. So I took the EGR valve off (not completely because I was worried of breaking the bolt that is attached to the side of the EGR with wires to it) It came off really easily from the bottom surprisingly. The actually nipple running to the vacuum modulator was completely plugged as well and I sprayed some cheap throttle body cleaner through it and shoved a nail through it to rid of the blockage. It did rid of it because when I sprayed the throttle body cleaner through, after a while the cleaner was coming out the end of the EGR valve tube (which is a good sign, right?) Further on, I sprayed TB cleaner into the place where the two bolts meet to the intake and got rid of some of the blockage although I don't know how far it goes. I took a small flat head screwdriver and scraped away at the crap until it seemed unblocked. I also did a test on the EGR valve itself as suggested above that the diaphragm may be ruptured. I connected hose to it and sucked on it to simulate the EGR being activated. My engine did I die, although it seemed as if the EGR wasn't sealed if that makes any sense. I'm entirely new to this and I just want my car to run properly so I can continue to invest into it, so try not to rag on me too hard lol. Not sure when you suck on the top portion of the EGR if it's supposed to be sealed or? I had to suck pretty hard for it to die out. Probably not a good sign. Who knows though. I'm only a beginner at this car stuff. Anyone willing to shed some light? I appreciate that there is such an active community willing to help me troubleshoot my problem.

[Smaay]

could also be the VSV under the intake manifold.

[brandon702bmx]

Are we talking about this?
http://www.ebay.com/itm/EGR-Control-Vacuum...4-/370911704609

Or this...?
https://www.summitracing.com/parts/smp-pvs1...9v7MaAopJ8P8HAQ


They are both respectively underneath the intake manifold...

[brandon702bmx]

EGR valve cleaned and CEL has come to say. Any relation? Desperately want to get this resolved so that I may start working on this car.

[brandon702bmx]

So my final question I suppose: Is there a way to physically test the diaphragm to see if its opening and closing all the way/properly? I will admit, since the EGR valve has been cleaned and unblocked I've noticed it driving a lot smoother gas mileage seems to have gotten better... CEL is still on though.

[Bitter]

There is, you need a vacuum gauge to test if it's opening under the correction conditions. It uses ported not manifold vacuum so it's a little tricky sometimes to work throttle and test stuff. Should be able to find some guides online for the 5S Camry, same tests as the 5S Celica.